Most manufacturers head down the route of building an all-in-one light with a custom battery inside (usually a derivative of a mobile phone battery or associated technology). But we've always pondered why someone doesn't just tap into the Ni-Mh market and run one of the current generation super bright LEDs from a couple of C cell or four AA cell widely available high capacity rechargeable Ni-MH batteries. Enter stage-left Dinotte.
A machined aluminium alloy body with a dent in it to fit against your bars and an o-ring to secure it, well sealed, waterproof, tough as old boots, containing the electronics (remember an LED is a solid state device, not a traditional bulb) and an on/off button. There is a wire running to a battery pack where you can place four AA batteries of your choice, even regular alkaline if you like. We ran Sony 2300 MAh Ni-Mh cells and we got just over 100 hours on high power setting, and over 180 hours on low power.
Double push (or click) the button to power on in low mode, single-push to switch to and from high power mode. It's simple, well made, and it offers a surprising amount of light in use. More than enough to see with, and plenty to be seen by.
Of all the single bright LED lights we've tested so far, this is by far the best and has the most commonsense battery solution of all.